sascwatch

Just signed up to see if someone could help me. My dad has a 2010 silverado with the 4.8L vortec engine and over the past 10000k or so we have noticed black soot on the rear fender near the exhaust and the exhaust pipes are VERY black inside.

More recently we have notice that when I start the truck when the engine is cold there will be a slight amount of smoke from the tail pipe, it has not burned any noticeable amount of oil over the last 2 oil changes done at 5000k intervals with conventional Penzoil 5w30 (not 100% sure that's correct).

We recently did about 3000k in a under a week all highway and ran a couple bottles of injector cleaner throughout the trip. Rear fender was pretty caked in soot. I should have check the oil levels when we returned but we've been busy cleaning our bears. Will check it ASAP.

So to sum up m problems:

1: VERY black exhaust pipes

2: black soot on the rear fender near exhaust

3: starting to smoke when started cold

Have about 75000k on the truck and have done oil changes every 5000. Only mods to the truck are a cold air intake and rubberized underbody coating which I just did last week.

I have been reading around about a valve cover issue with some 2010 silverado's and sierras that causes oil to sit in the valve cover when shut off and then it gets burnt upon startup.

Before I take it to the dealer Id like the have somewhere to start, I think the issues I'm having should be warranty-able. Anyone have any suggestions on where to begin? I will be checking oil levels tomorrow or thursday when I go to my dads house. With my dad being disabled with a broken back he isn't capable of doing this work himself.

Thanks in advance.